The following acronyms are used in the description that follows:
ACLR adjacent channel leakage ratio
FE front-end
FM frequency modulation
GPS global positioning system
GSM global system for mobile communications (2G)
LTCC low temperature co-fired ceramic
LTE long term evolution of UTRAN (E-UTRAN or 3.9G)
MEMS micro electro-mechanical system
MIMO multiple input multiple output
OFDMA orthogonal frequency division multiple access
PIN P intrinsic N
RF radio frequency
RFID radio frequency identification
TIS total isotropic sensitivity
TRP total radiated power
UTRAN universal mobile telecommunications system terrestrial radio access network
WCDMA wideband code division multiple access (3G)
WLAN wireless local area network
This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Increasingly, mobile radio terminals/handsets incorporate multiple radios (for example, one or more primary radios using various cellular technologies such as GSM, UTRAN, WCDMA, OFDMA; and one or more secondary radios such as WLAN, Bluetooth, GPS, RFID and broadcast FM radio receivers) that operate over different protocols and different frequency bands. Each of these radios must operate with an antenna tuned to the requisite frequency band though sometimes an antenna may operate in two or more radio frequency bands. And for hand-held devices such as mobile stations, all this hardware of course must be tightly arranged in a small package with attention to preventing interference between them.
A problem with a multiple antenna system is that a radiated signal of a first antenna is coupled to a second antenna and thus a radiated performance of the first antenna is decreased.
The radiated performance of the first antenna is altered in different use cases due to a change of a complex antenna isolation between antennas. Such use cases are for example whether the mobile terminal is resting on a table, in the user's hand, and/or touching the user's cheek.